The cartridges known hitherto comprise an effective charge or a plurality of effective charges arranged in series.
In the infrared range, the effective charges are grains of pyrotechnic substance produced from low-performance compositions, and these grains will therefore be of relatively large size in order to produce an infrared signature equivalent to that of the platform to be protected.
The disadvantages resulting from this are the large size of the cartridges, which limits their number for a given overall size of the ammunition. The ejection charges must be of high power, thus implying a sharp recoil when the shot is fired and necessitating reinforced and therefore heavier parts (such as the rack or the plate).
In the ammunition of the above described type known hitherto, the cartridges are fastened in the rack one by one by means of screws or elastic stop rings (circlips); the plate likewise closes the rack by screwing. The disadvantages of such devices are the loading difficulty, which necessitates a more or less specific tool, and the duration of this loading which is attributable to the numerous manipulations. Under these conditions, the reloading of the rack is impossible at the operations site.